There are so many different kinds of cloth diapers around. One hears about all in ones, two in ones, prefolds, flats, and diapers that are cute and leak without a cover. Most people don't want to try out every system to figure it all out. I would not have tried everything I could think of if I had only had a few kids, but I have had up to three kids in diapers at the same time and one needs to find the diapers that work best for this situation.
The AIO diaper is super easy. If I did not want to stuff diapers, then this is a good system. You put the diaper on and you are ready to go. With an older baby, getting solid waste of these diapers is not super fun, but most of the time one can shake it into the potty and be done. I sometime use a liner made of hemp so it soaks up more liquid and I can just take that and shake solid waste into the potty. I know one can buy liners that flush down the toilet, but I have not found much data on if that works well with a septic, plus it is added cost. Why would one not like AIO cloth diapers? They take more time to dry. That is the main difference for us. I gave into the dryer time because my husband I have so many diapers to change it is nice for everything to be ready to go.
The cover and fitted diaper combination is another favorite of mine. I love this system because the fitted diaper has elastic and so does the cover, so the chances of a mess are rare. Even with an infant I did not have blowouts. These diapers can be dried a bit faster on high heat and one does not need a cover for each diaper. I have made it with two to four covers using this system. The down side, you have an extra set of Velcro or snaps to deal with. This is not that big of deal of course. Also, if one wants to use a ruffle cover it could last longer than one diaper cover. I loved using ruffle diapers under my baby girl's dresses. Sometimes they even matched.
I am not making pocket diapers because I myself got sick of stuffing diapers, but this system can work like the fitted and covers, only one needs a cover for every insert. One can use extra inserts for a baby that gets too wet. Prefolds also work as inserts. It can work well for many families. I would rather lay a booster in an AIO or a fitted diaper for long car trips and nights.
If I ever find time to knit, I would like to make some wool covers. These were great with an infant because they kept my baby very dry and the fit was perfect. Some PUL covers are too bulky with a tiny baby. One can also make covers out of old wool sweaters. I have seen some really cute wool covers on different websites.
Really, the best system is up to the buyer. The cheapest way to cloth diaper is to buy 2-4 covers and 12-24 prefolds and the system that requires little work is the AIO cloth diaper system.